Process for rapid hardening of cement.



106. COMPOSITIONS,

COATING OR PLASTIC.

9 w N D ST T S PATENT OFFICE:

H'EEMAN sonnnlnnn, 01 NCINN TL' HI Pnocsss oe RAF-"JP; HQBDENING oF CEMENT.

To It whom it may concern:

' Be it known that I, HERMAN SCHNEIDER, a citizen of' the United States, residing in "Cincinnati, county of Hamilton, and State of 5 Ohio, have invented a certain new and'useful Process for the Ra id Hardenin "of lerrien't, of which the fol owing is a fufi, clear, and exact descri tion. i

'My process re ates to the novel treatment of cements, both natural and artificial sucl i as are employed for buildin purposes, paving, and the likeand whet 'er employedas neat cement or mixed to form concrete material or cement-mortar; and the purpose of r 5 my invention is to hasten to a very marked degree the hardening and setting of the dement material both initially and-permanently and at the same time so to heat the material that it may be treated and used in cold and frosty weather without detriment. My invention, broadly considered, consists in sub'ectin the cement material whether concre e, cem ter it has been mixed with Water to the action of a urrent of electricitof the requisite strength to suit the requirements.

As is well known, the setting of hydraulic cements is a comparatively slow process, the length of time to obtain the initial and the 0 permanent set of the material depending on the qualities of the cement and the proportions and character of the mixture. Many varieties of natural and Portland cement are manufacture an various mixtures o sand 3 5 for cement-mortar and of sand and ravel cinders, or broken stone for concre e are emye an I ese ma erials and mixtures are used when mixed with either an excess or only a minimum quantity of water for a great variety of building and paving purposes.

For whatever purpose the cement mate rial is intended to be used, whether to be molded into blocks or employed for concrete columns or floorin or for the uniting together of stone an brick Work, I have discovered that if the material as soon as it has been mixed with water is subjected to a current of electricity the assage of the current has a very marked e ect on the set of the material.

In carryin out my process I aim to pass the current t ough the body of the material and continue the application until or after the material has its permanent set. Where blocks of the cement material are formed in a mold, I provide metal plates for opposite Specification of Letters Patent. Application filed April Serial I10. 314.050.

Patented Aug. 21 1 966,

faces of the block and connect the positive' Cross Reference 8Z8 yyer indirect pathsthrough the material more open to it until the entire mass becomes permanently set and loses in a measure its conductivity. Moreover, as the resistance in.- crea'ses as the material hardens heat is generated, which raises the temperature of the mass.

In the construction of concrete flooring it is the usual practice to embed in the top and bottom surfaces of the material metal rods to enhance the tensile and compression strength of the structure. In such cases I connect the current-wires, one to the upper and the other to the bottom metal bond, and continue the application until the mass has set permanently and as long thereafter as may be desired. For beams and columns of concrete, in which it is also customary to embed strenfgthening metal rods, I use one rod or set o rods for my positive terminal and another rod or set of rods for the negative terminal, so that the current shall pass as completely as may be through the entire mass.

Without attemptin to oint out in detail the exact application or t e great variety of purposes for which cement material is employed, Whether neat cement, concrete, or cement-mortar, it will be obvious from the foregoing descri tion how the electric current is to be app ied. At or near one surface I form a ositive terminal and at or near the opposite surface I form a ne ative terminal and the current asses until automatically a substantially uniform hardening of the mass results. r

The increased resistance of the constantlyhardening cement raises the temperature and facilitates the setting in cold and frosty weather, so that with my process there is no danger of the mass freezin or that frost will destroy the permanency o the structure before or after the permanent set of the material. The length of time required for the setting depends somewhat on the character and qualities of the particular cement and the proportion of the mixture and also, naturally, on the thickness or volume of the mate- ICC IIO

.may be used the e .is very marked. A small sam le-block of rial under treatment. The strength of the electric current should be gaged in accordance with the mass to be treated. Quite a wide range of current may be employed. A current of low intensity will act more slowly in setting the material but with longer application good results can be obtained, While the current should not be stron enough to raise the temperature to the boifing-point of Water, as will be obvious.

Whatever descri tion of cement material fi zect of the electric current material, which under natura conditions will take a day or more to receive its'permanent set, will, when treated with electricity, as above described, receive its permanent set in fifteen or twenty minutes.

Concrete flooring, which takes several days to set permanently, when treated with the current sets permanently in a few hours. Not .only is the setting of the material greatly enhanced and the temperature raised, so that .there is no danger from frost, but there is no decrease of its tensile and compressive stren th.

I 0 not Wish to confine myself to any theory in explanation of the effect of the current in hastening the setting of the cement material; but,

Having fully described my novel process, what I claim as new, and desire to secure by Letters Patent, is

1. The process for the rapid hardening of cement, which consists in subjecting the ce- 1 i A f. 828,956

mentmaterial, when mixed for use, to a current of electricity, substantially as described.

2. The process for the rapid hardening of cement, which consists in passing a current of electricity through the cement material, when mixed with water, and continuing the current until or after the mass receives its permanent set.

3. The rocess for the rapid hardening of cement, which consists in passing through the cement material, when mixed with Water, a current of electricity of a strength sufficient to heat the mass to prevent freezin 4. The process for .the rapid hardening of cement, which consists in embedding in the opposin surfaces of the mass of cement material w en ready for use, the positive and negative terminals from a source of elec tricity, and in passin the current therethrough until or after t e mass has obtained its permanent set.

5. The process for the rapid hardening .of cement, which consists in embedding in the opposin surfaces of the mass of cement material w en ready for use, the positive and negative terminals from a source of elec tricity and in passing the current therethrough until or after the mass has obtained its permanent set, said current being of sufficient strength to heat the mass to prevent freezing.

HERMAN SCHNEIDER. Witnesses:

GLENA PRITOHARD, EDW. C. MATLOCK. 

